In a vehicle, right and left side frame members are provided at both sides of the vehicle in the longitudinal direction thereof, and cross frame members extend in the lateral direction of the vehicle and connect the right and left side members to one another are provided at front and rear sides (i.e. ends) of the vehicle. In some types of vehicles, an evaporation system having a canister is provided together with a fuel tank.
In this evaporation system, a canister is provided in between an evaporated fuel pipe in which an evaporated fuel passage communicating with the fuel tank is formed and a purge pipe in which a purge passage communicating with an air intake system of an engine is formed, and a purge valve for opening and closing the purge passage in response to an operating state of the engine to control a rate of introduction of evaporated fuel into the air intake system is provided at a point in the purge pipe. The canister accommodates therein an absorbent such as activated carbon, absorbs evaporated fuel in a fuel tank by means of the absorbent when the engine is stopped, purges the absorbed evaporated fuel by means of atmospheric air introduced thereinto when the engine is operating, and supplies the fuel to the engine. The air provided to the canister is introduced from an air suction pipe member comprising a hose connected to the atmospheric side of the canister.
Such an evaporation system is disclosed, for example, in Japanese Patent Laid-Open Publication No. 09014060A (1997). According to this publication, by providing an air hose which is an air suction pipe member with one end thereof connected to a bottom of the canister and the other end thereof inclined downwardly to reach the side of the vehicle body frame, deposition of water in the air hose is prevented.
In the conventional type of evaporation system, however, when fuel is supplied to a fuel tank, the air in a canister pushed by evaporated fuel from the fuel tank is rapidly introduced to the atmospheric side of the canister, so that the distance from the canister to an inlet/outlet port at the end of the air suction pipe member should preferably be made shorter because air flow resistance within the air suction pipe member becomes smaller, but no attention has been paid to this point in the conventional technology. For this reason the length of the air suction pipe member is normally long, and the flow resistance is disadvantageously great.
In addition, when the canister purges and supplies a large quantity of evaporated fuel to the engine, a large quantity of air is introduced from the air suction pipe member into the canister, and a large amount of dust is disadvantageously introduced into the canister together with the air.
Further, when the inlet/outlet port in the atmospheric side of the air suction pipe member is provided around in the vicinity of the fuel tank adjacent the rear side of the vehicle, the inlet/outlet port is located at a position closer to the ground than the engine compartment or the like so, that the quantity of dust introduced into the canister increases.
Further, on some vehicles provided with an internal combustion engine, an evaporated-fuel collecting apparatus is provided for the purpose of preventing leakage of evaporated-fuel generated in the fuel tank to the outside. The evaporated-fuel collecting apparatus has a canister provided therein for collecting evaporated-fuel generated in a fuel tank, absorbing and maintaining the fuel, purging the absorbed and maintained evaporated fuel when the internal combustion engine is operating, and supplying the fuel to an air intake passage for the internal combustion engine.
The evaporated-fuel collecting apparatus also has a valve provided therein for opening or closing the interior of the canister to the outside air. Opening of the valve permits communication between the interior of the canister and the outside air for the purpose of purging the evaporated fuel absorbed by the canister and supplying the fuel to an air intake passage through a purge passage, and closing of the valve prevents communication between the interior of the canister and the outside air when checking for any leakage of the fuel to an evaporating passage.
An example of this type of evaporated-fuel collecting apparatus is disclosed in Japanese Patent Laid-Open Publication No. 08058404A (1996). This Publication discloses a vehicle having a rear floor panel provided at the rear side of a connecting wall standing upward at the rear edge of a front floor panel, and a fuel tank is supported adjacent the lower side of the rear floor panel. A canister is located in a section between the rear face of the connecting wall and the front face of the fuel tank.
In the conventional type of evaporated-fuel collecting apparatus, however, when a canister for collecting evaporated-fuel in the fuel tank is to be mounted on the body of the vehicle, the fuel tank and the canister are discretely or individually mounted on the body as separate components, and the fuel tank and the canister are then connected to one another by a hose. As such, in the conventional type of evaporated-fuel collecting apparatus, time, steps, and a number of components required for assembling the components to the body of the vehicle tend to increase.
Also, since the canister is located near the fuel tank in the rear side of the body of the vehicle, an absorbent such as activated carbon inside the canister is easily effected by the outside air temperature. For this reason, when the outside air temperature is low or the canister is cooled by wind or air flow during driving of the vehicle, the temperature of the absorbent in the canister is lowered, which reduces purge capability.
Further, in the conventional type of evaporated-fuel collecting apparatus, when a valve for communicating or cutting off the interior of a canister to or from the air is to be mounted on the body of the vehicle, the canister and the valve are discretely or individually mounted on the body as separate components, and the canister and the valve are then connected to one another by a hose. For this reason, in the conventional type of evaporated-fuel collecting apparatus, time, steps, and a number of components required for assembling the components to the body of the vehicle tend to increase. Further, the canister and the valve are separately assembled, which results in inefficient use of space within the vehicle.